It's a classic case of "who done it?" this week. That could spell trouble for Nate, as teased in this promo for Leverage.
Added:

Leverage Season 4 Episode 2 Quotes

Hardison: Nate killed someone?
Eliot: Nate didn't kill anyone.
Parker: But you would tell us though, wouldn't you?
Nate: Yes Parker, I would tell you if I murdered the mark.

Eliot: This is a bad idea; the way I normally get information out of guys is messy
Nate: Tonight you are a grifter, adapt.